Internal-combustion engine



Feb. 13, 1951 M. MALLORY 2,541,594

INTERNAL-COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed Sept. 11, 1947 FIG. 1.

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penul- M. MALLORY INTERNAL-COMBUSTION ENGINE Fgb. 13, 1951 2Sheets-Sheet 2 Filed Sept. 11, 1947 INVENTOR. Mar/on Mafia/y PatentedFeb. 13, 1951 2,541,594

UNITED STATES PATENT OFFICE I 2,541,594 INTERNAL-COMBUSTION moms MarionMallory, Detroit, Mich, assignor to The Mallory Research Company,Detroit, Mich., a

corporation of Michigan Application September 11, 1947, Serial No.173,429

7 Claims. (Cl. 123-61) This invention relates to internal combustionengines of the type empoying opposed pistons, and comprises operatingthe pistons from separate cranks, one having a longer throw than theother, and rotating the cranks in unison but with the shorter crankhaving a lead over the longer crank. w

An object of the invention is to so relate the pistons and their crankoperation that at least one of the pistons will be at an advantageous lfor a considerable time after crank it has passed angle when the chargeis fired. ..dead center. 'As crank it moves farther from Another objectof the invention is to relate dead center, piston [2 speeds up, and ascrank pistons operated in the described manner so that it approachesdead center piston il slows down, they function advantageously withcentrally so the space between the pistons is least, slightlycatedexhaust and intake ports governed on the 1 before crank Ill reaches deadcenter, but with 4-cycle principle. crank l8 past dead center. Thefiring will, of Another object of the invention is to relate course, berelated to the minimum capacity of pistons operated in the describedmanner so that the space between the pistons in the same way theyfunction advantageously with exhaust and it is related to dead center ofthe piston in the inlet ports near opposite ends of the cylinder usualone piston 4-cycle engine. where they are uncovered by the outer ends ofAs will be seen from the drawings, the firing the travel of therespective pistons. takes place just before the position shown in Fig.Other objects and advantageous details of the 1 is rea and w a k itnearly 5 past inven ion will appear as the description proceeds deadcenter and crank 15 nearly on dead center. in connection with theaccompanying drawi Therefore, while the beginning of the working whichform a part of this specification. stroke finds crank [5 in nearly thesame position In the drawings, Fig. 1 is a diagrammatical as in theusual one-piston en in rank 15 i longitudinal section of an engineembodying the very advantageously angled so that the force presentinvention near the beginning of its workapplied on piston l2 has goodleverage on ing stroke. Figs. 2, 3 and 4 are views similar to .u. ShaftFig. 1 but showing the position of the parts near As w b readilyunderstood o 2. G an the beginning of the exhaust stroke, intake strokeIt continues to move piston ll rapidly Outward and compression stroke.respectively, and Fig. 5 after crank i6 has p s O ter d r. 80 is aperspective detail of the valve control cams the distance between thepistons continues to of Fig. 1 and theirv operating parts. increaseuntil crank it is well past dead center. In the construction shown inthe drawings, Accordingly, the work stroke continues and the there is?cylinder it in which there operates opexhaust valve need not open untiljust before the posed pistons II and I2. Crank shaft: is and positionshown in Fig. 2. M with cranks I 5 and I6 are provided for oper- The endof the exhaust period and beginning ating the pistons, the shafts beingconnected by of the intake period, indicated in Fig. 3, finds gearing sothat the shafts rotate at the same the pistons moving as described abovein conspeed but with the short crank it leading the nection'with Fig. 1,and the end of the intake longer crank it. period and beginning of thecompression period, The cylinder has a centrally located intakeindicated in Fig. 4, finds the pistons moving as port l9 controlled byan inwardly opening valve described in connection with Figv 2. so thesenosi- 20 admitting charges'through a passage 2| from tions need not bediscussed in detail. As will be a connected carburetorinot shown) in theusual seen,- the engine operates substantially like the manner. Thecylinder is also provided with a usual one piston, 4-cycle engine exceptfor the centrally located exhaust port 22 controlled by highlyadvantageous angle of crank it at the bean inwardly opening valve 23.Valves 20 and 23 5o ginning of the working stroke that results in arenormally closed by the springs 24 and 25, remore efi'ective use of theinitial high pressure, spectively, as will be readily seen. They are andthe continuing e'p ns on of the cham er opened by the respective cams 26and 21 .on cam by relatively fast moving piston ll at'the end of shait28 geared to the crank shafts to turn once the working stroke whichhelps to utilize the final to every two rotations of the crank shafts.Cam ll relatively low pressure at the end of the stroke.

' Likewise .Ionj stroke-the concurrent high I throwsand driven inangular. outer travel offpi'ston I: added to the normal outer travel ofpiston ll results in a more exerted at the start of the intake stroke.

Atthebeginning-of the exhaust stoke the inward movement of piston I2 islikewise rapid. and

the reduction in effective capacity of the cylinder is more rapid at thebeginning of the exhaust and compression strokes than it would be in asingle piston engine. This hastens the expulsion of the exhaust gasesand conseouently leaves less gas for expulsion at the end of the exhauststroke and likewise results in increasing the relative rate ofcompression at the beginning of the compression stroke when'theresistance is comparatively light.

While some of the advantages will result from v any lead of the 'shortcrank over the long crank up to a lead of 90, the illustrated lead ofabout 45 is preferred, or a variation'within the range 5 30 to 60. .Theillustrated proportionof 2 to 1 in the lengths of cranks produces aneffective result, but other proportions obtain some of the advantages. 0

As has been seen, .the described relationof cranks and pistons has theadvantages on eachof the four strokes of a 4-cycle engine, and thereforecan be very advantageously used for that purpose. However, the same orapproximately the same, arrangement of pistons and cranks ha advantagesfor 2-cycle operation. Instead of the centrally located intake andexhaust ports with their valve control, an exhaust port indicated at 33by dotted lines may be uncovered by piston l2 at the outer end of itstravel, and an intake port indicated at 34 by dotted lines may beuncovered by piston II at the outer end of its travel. The inlet opening34 may be conoperatively connected; to each piston, onefof saidtageously as either a 4-cycle or 2 -cycle, ngine some of the advantagesof '2. internal combustion engine comprising 1'4" unison but with'pon 'aleadfover 'the other, may be utilized-adva and that many variations maybe made, a

n njs proportion of. throw or the lead while reta the invention.f

WhatIclaimis: i

1'. 'An internal combustion engine comprisin'g'aj J 0 cylinder, opposedpistons in the cylinder,- a{ crank operatively connected to each'piston, oneof said cranks having a greater throw than-theiother,',' f vand means to rotate the cranks in unison at the I same speed but withthe crank having the lesser throw having a lead of not morethan 90 overthe crank having the greater throw. Y

a .cylinder, opposed. pistons in the cylinder, a crankoperativelyconnected to each piston, one of 'saidcranks having a throwapproximately twice as great as that of the other crank, and meansrotating the cranks in unison at thes'ame speed but with theshortercra'nk having alead of between 30 and 60 over the other crank. 3.An internal combustion engine-comprising a cylinder, opposed pistonsinthe cylinder, a crank cranks having a greaterthrow thanthe other, 9and means to rotate the cranksin unison but with the crank having thelesserthrow having.

a lead of not more than 90 over the crank having I. I I the greaterthrow, the cylinder havingcentrally. I

, located exhaust and inlet ports, valves controlling" of said crankshaving a throw approxi nected to a source. of air under pressure, not

shown, and the fuel may be mixed withall the air introduced through theinlet or the final portion of the air only, or by any suitable separatemeans.

It will be seen that the advantageous beginning of the firing strokewill apply the same when employing the ports 33 and 34 as when ports l9and 22 are used. However, when operating on the 2-cycle principle, theexhaust port 33 is opened before piston l2 reaches outer dead center,and so the working stroke is shortened, and the exhaust is completed bythe-time the position shown in Fig. 2 is reached. The charging with airvmay continue thereafter until port 34 is covered by piston l I, and thefuel may be injected at this time or later by any suitable means.position of Fig. 3 is reached, a new charge has When the been compressedand fired, as described in connection with Fig. l. a r The opening ofthe exhaust prior to the opening of the intake and the closing of theexhaust prior to the closing of the intake is automatically secured bythe described arrangement, and variopposed pistons operated by crankswithdiiferent 'and'60 over the-other crank, the cylinder having theshort crank passes inner dead center and 'coveredfby the outer end ofthe travel-of the .same speed but with the crank having the lesser theports, and means timing thezvalves'for 4 cycle operation. r v 1 4. Aninternal combustion engine comprising a cylinder, opposed pistons in thecylinder, a- 1 crank operatively connected to each piston, one

twice as great as that of the other crank, and, r means rotating thecranks in unison but with the shorter crank having a lead ofbetween 30centrally located exhaust and inlet ports, valvesui controlling theports, and means timing the valves for 4-cyc1e operation, and for firingafter beforethe long crank passes inner dead center.

5. An internal combustion engine comprising a cylinder, opposed pistonsin the cylinder, a crank operatively connected to each piston, one ofsaid cranks having a greater throw than the other, and means to rotatethe cranks in unison at the samespeed but with the one crank having a a.lead of between 30 and over the other If crank, the cylinder having anexhaust port un piston having the lead and an inlet port ung covered bythe outer end of the travel of the-other piston'.

6. An internal combustion engine comprising i a. cylinder, opposedpistons in the-cylinden'a'crank operatively connected to each piston,one of said I cranks having a greater throw than the other,

and means to rotate the cranks in unison at the throw having a lead ofnot more than 90 .over the crank having the greater throw, the cylinderhaving an exhaust port uncovered by the outer end of the travel of thepiston connected to the short crank and an inlet port uncovered by theouter end of the piston connected with the long crank.

7. An internal combustion engine comprising a cylinder, opposed pistonsin the cylinder, a crank I operatively connected to each piston,oneofsaid CES CITED The following references are of record in the fileof this patent:

Number Number 8 UNITED STATES PATENTS Name Date Hardy July 15, 1913 TothDec. 4, 1923 Junkers Feb. 18, 1936 FOREIGN PATENTS Country Date Italy of1930' France of 1935 France of 1939

